Rocky Mountains

The Rocky Mountains are a very long line of mountains.

They start far north in Canada and go all the way south into the United States. Some peaks have snow and ice on top. Bright blue lakes sit in the valleys.

The Rocky Mountains are the great backbone of western North America. They stretch about 4,800 kilometers, from northern Alberta and British Columbia in Canada south to New Mexico in the United States, and in places they are more than 480 kilometers wide. To the east lie the flat Great Plains.

The Rockies are not one single chain. They are made of at least 100 separate ranges, grouped into the Canadian and Northern Rockies, the Middle Rockies, the Southern Rockies and the Colorado Plateau. Many peaks are higher than 4,000 meters. The highest is Mount Elbert in Colorado, at 4,399 meters, and Colorado alone has 53 peaks over 14,000 feet, about 4,270 meters.

Britannica describes the Rockies as the cordilleran backbone of the great upland system of western North America, extending some 4,800 km from northern Alberta and British Columbia to New Mexico and more than 480 km wide in places, though their limits are partly arbitrary, especially in the far northwest. They are bordered on the east by the Great Plains and on the west by the Interior Plateau and Coast Mountains of Canada and the Columbia Plateau and Basin and Range Province of the United States.

The at least 100 ranges fall into four groups: the Canadian and Northern Rockies, the Middle Rockies, the Southern Rockies, and the Colorado Plateau. They differ in geology and landforms but share high elevations, with many peaks above 4,000 m, local relief of typically 1,500 to 2,100 m from base to summit, shallow soils, mineral wealth and glacial scenery. The Southern Rockies are the highest: Colorado has 53 peaks above 14,000 feet, led by Mount Elbert in the Sawatch Range at 4,399 m. The Canadian Rockies drain about equally east, to the Atlantic and Arctic, and west, to the Pacific.

Many animals live in the Rockies.

Mountain goats and bighorn sheep climb the high rocks in summer. Elk and bears live in the forests. A tiny pika lives among piles of rocks.

The Rockies change with height. Lower down there are forests of aspen and pine; higher up, spruce and fir; and above the tree line, alpine tundra with low flowering plants. Wildflowers such as columbine and Indian paintbrush brighten the forests and high meadows.

Britannica lists black bears, grizzly bears, mountain lions and wolverines among the big animals of the backcountry. Bighorn sheep and mountain goats live on high cliffs in summer and move lower for winter, and elk and deer move up and down with the seasons too. The little pika lives on rocky slopes. Wolves, almost wiped out by people, have been returning since 1970.

Britannica describes two broad climate zones over much of the range: cool temperate, roughly 2,100 to 3,000 m in the south, and alpine tundra above, with both limits falling northward. Montane forests of aspen, yellow pine, piñon and Douglas fir give way to subalpine forests of lodgepole pine, spruce and western hemlock, then to alpine tundra that spans nearly the whole range; precipitation in the north is about three times that of the south.

The fauna is varied: black and grizzly bears, mountain lions and wolverines; bighorn sheep and mountain goats that summer on high crags and winter lower; caribou, elk, mule and white-tailed deer migrating between alpine meadows and subalpine forest; moose in the north; bison at Yellowstone; pikas on talus and marmots, ground squirrels and black-footed ferrets lower down. Wolves, brought near extinction by people, have resurged since 1970. Birds include bald and golden eagles, osprey, peregrine falcons, ptarmigan, Clark's nutcracker and the endangered trumpeter swan. UNESCO's Canadian Rocky Mountain Parks also protect the Burgess Shale, whose soft-bodied fossils from soon after about 540 million years ago give key evidence of the early evolution of most animal groups.

People have lived in the Rockies for thousands of years.

Many Native American and First Nations peoples still live there. Today many people visit the mountains to hike and see the animals in big national parks.

People have lived in the Rocky Mountains for at least 10,000 years. Native American and First Nations peoples whose homelands include the Rockies include the Kutenai, Nez Percé, Shoshone, Ute, Navajo and many others.

The Rockies were one of the last parts of North America that Europeans explored, because the land is so rugged. Alexander Mackenzie crossed them in 1792 to 1793, and the Lewis and Clark Expedition crossed in 1804 to 1806. Miners later came for copper, silver and gold. Today many of North America's finest national parks are here, including Banff, Jasper, Glacier, Yellowstone, Grand Teton and Rocky Mountain National Park.

Britannica dates human presence in the Rockies to 10,000 to 8,000 BCE. Peoples of the northern ranges include the Shuswap and Kutenai of British Columbia, the Coeur d'Alene and Nez Percé of Idaho, and the Salish of Montana; Shoshone and Ute lands extended into the west-central ranges; the Hopi and other Pueblo peoples and the Navajo live in the southwest; and Plains nations such as the Blackfoot, Crow and Cheyenne ranged into the eastern Rockies. Britannica notes that contact with Europeans from the 16th century brought migration, loss and conflict, and many Native Americans now live on reservations in the region.

European exploration came late: Escalante in 1776 to 1777, Mackenzie in 1792 to 1793, Lewis and Clark in 1804 to 1806, David Thompson in 1807 to 1811, Jedediah Smith in 1822 to 1831, Frémont in the 1840s, and four great U.S. surveys after the Civil War. Mining of copper, silver, gold and molybdenum, oil, gas and coal, and dams that send water to cities such as Denver followed. Britannica calls the Yellowstone area one of the largest relatively intact temperate-zone ecosystems on the planet. UNESCO's Canadian Rocky Mountain Parks, inscribed in 1984, cover some 2.3 million hectares, over 95 percent kept in a natural condition, and note that glacier recession due to climate change is evident there.